1. Field of the Invention
The present invention pertains to a structure for preventing movement of pivot bearings, for example, pivot bearings as used in a wiper device for vehicles such as passenger cars, buses, and trucks.
2. Description of the Related Art
As is commonly known, in this type of a wiper device, a pivot shaft, having a wiper arm integrally fixed at its base end, is rotatably supported by a sleeve fixedly mounted on a vehicle body through the intermediary of a pair of bearings opposedly placed at a predetermined axial spacing from each other.
In the above wiper device, bearings are press-fitted in the sleeve in which the pivot shaft rotatably slides with respect to the bearings. However, the press-fitted bearings may axially move to get close to each other when the press fitting between the sleeve and the bearings becomes loose due to an unacceptable allowance of the press fitting or thermal expansion and contraction caused by temperature variations. Under this circumstance, reliable supporting of both ends of the pivot shaft by the bearings will be impaired and smooth oscillation of the wiper arm is prevented due to the shaking of the pivot shaft and so on.